Fluid Flow – Section 1

41. Reynolds number for laminar flow over a plate should be less than

A. 500 mm
B. 5 x 10^-5
C. 5 x 10⁵
D. 5 m

42. The approach which is commonly used to determine the level of damage to animal cells in a culture medium is to monitor

A. the concentration of lactate in the medium
B. the level of lactate oxidase activity in the medium
C. the level of lactate dehydrogenase activity
D. the level of lactase activity in the medium

43. A Brookfield viscometer cannot determine the shear stress because

A. the shear stress is not defined
B. a computer is required
C. the impeller type is given only by numbers
D. all of the above

44. Which of the following is correct?

A. The viscosity of liquids and gases decrease with increasing temperature
B. The viscosity of liquids and gases increase with increasing temperature
C. the viscosity of gases increases with increasing temperature but decreases in liquids
D. the viscosity of gases decreases with increasing temperature but decreases in liquids.

45. The Komologorov eddy size

A. is constant at all stirrer speeds
B. increases with stirrer speed
C. decreases with stirrer speed
D. becomes zero when the stirrer speed is very low